I conducted an experiment last month with cover designs for my first ebook, "Dropbox In 30 Minutes." I measured the Amazon sales for the book using different covers (DIY and a professionally designed cover). You can see the data and the evolution of the designs on the following page:

Interesting experiment, but I would say that you used way to short of a window to know.

Yes, I agree that the window was short and the sample size could have been larger. And as I noted in the post, other external factors may have influenced the data.

Nevertheless, I think there are enough sales and a big enough change between the two periods (average increase of 50% per day) to indicate that there was at least some positive impact from the design change.

ilamont: Thanks for posting that, it was interesting. I quite liked your first cover (though there are issues: background of the photo, was the use of the logo permitted, etc.), but agree that the professional job suits the work much better ... I'm trying to work out whether the fact that it reminded me of the "... for Dummies" series was a good thing or a bad thing.

But on the subject of professional cover designs: not all of them are so great. I see quite a lot come out that are so obviously cobbled together from clipart and seem to offer little in the way of making a book look appealing. This is true even (especially?) on books by big names published by big publishers.

I am not certain that there is anything anyone can do to make a book reliably stand out from a page full of small thumbnails - especially when matched up against books of the same genre (eg: your book up with "for Dummies" books, or a page full of erotica books where all the covers are half-naked men or women). But certainly the cover should look attractive on the larger thumbnail (when displayed on it's own or with a small selection of other books. Your blog links to a kindleboard page as an example of "pro covers", and while I agree that individually most look good, few really stand-out in their small thumbnail form.

I think this is a bit like something I said on another thread about the importance of the first pages in a novel: first do no harm ... and after that you can worry about doing good. I don't think your first cover did any/much harm, and it seems to me your sales reflect that.

On the subject of professional cover designs: not all of them are so great. I see quite a lot come out that are so obviously cobbled together from clipart and seem to offer little in the way of making a book look appealing. This is true even (especially?) on books by big names published by big publishers.

I am not certain that there is anything anyone can do to make a book reliably stand out from a page full of small thumbnails - especially when matched up against books of the same genre

Thanks GMW. I too have seen some bad cover designers out there; I'm not even sure I would use the word "professional" to describe their work. There are also the designers who work with very formulaic templates (Harlequin romances, etc.). It's not my cup of tea, but on the other hand it may be what their readers expect, and the designers don't have much flexibility to do something original or bold.

For those designers who do have good-looking covers, I've always wondered about their processes -- are they working from templates? How much back and forth takes place with the author? My designer came from the magazine world, which has a certain way of working with clients (lots of design comps, iterative process, etc.) but that may not be normal.

As for your thumbnail point, I think it really depends on the genre. For mystery novels, I think it will be hard to stand out because authors are using the similar fonts, themes, colors, etc. For my genres (software/education/reference) there is a lot of variation, and a lot of poorly done covers, which makes it easier to stand out if you have something bold or striking.

Someone asked me why I didn't use the blue cover in the second set of designs (Dropbox is blue, and it looks more aesthetically pleasing). My answer: When I shrunk it to thumb size and superimposed it over the Amazon search for "Dropbox book" it didn't really stand out. The orange cover does (you can try this yourself, save the image from my blog and then crop it to the different colors, and superimpose it over the same search terms).

It is very obvious to me which set of covers I'd like my work to be associated with. The question really is whether the income from the book will meet the cost of the cover.

DrNefario: Assuming a 25% increase in sales from the new cover over time, and at the current sales rate, I'll should have a positive return on this investment sometime in October (September has been slow).

FWIW, he charged an hourly rate that worked out to be absolutely competitive with the flat rates that I see bandied about.

Someone asked me why I didn't use the blue cover in the second set of designs (Dropbox is blue, and it looks more aesthetically pleasing). My answer: When I shrunk it to thumb size and superimposed it over the Amazon search for "Dropbox book" it didn't really stand out. The orange cover does (you can try this yourself, save the image from my blog and then crop it to the different colors, and superimpose it over the same search terms).

For Ebooks this is all that really matters. The cover AS A THUMBNAIL must look:

1) DIFFERENT enough to stick out and draw the eye.

2) INTRESTING enough to cause the shopper to look to learn more.

IMO nothing else about the cover really matters. The hard part is doing that.

In Ebook land, the full size cover is almost completely impact-less, only the thumbnail matters. IMO